1. Technical Field
The present disclosure relates to an electrolytic capacitor including a dielectric layer formed by anodization and a manufacturing method therefor.
2. Background Art
Recently, a small-sized and large-capacity capacitor for high frequency has been required according to a reduction in size and a reduction in weight of electronic devices. An electrolytic capacitor having small equivalent series resistance (ESR) and excellent frequency properties has been developed as such a capacitor. The electrolytic capacitor includes an anode body containing valve action metal such as tantalum, niobium, titanium, and aluminum, a dielectric layer formed on the anode body, and a cathode body. Among electrolytic capacitors, the electrolytic capacitor in which a solid electrolyte layer (hereinafter, simply referred to as a conductive polymer layer) containing a conductive polymer is formed on the dielectric layer as the cathode body is referred to as a solid electrolytic capacitor.
The dielectric layer is formed by performing a chemical conversion treatment (that is, anodization) to a part of the anode body. The chemical conversion treatment of the related art is performed by dipping the anode body into a chemical conversion liquid, such as an aqueous solution of phosphoric acid, and by applying a current between a cathode electrode and the anode body (an anode electrode) (for example, refer to Japanese Patent Unexamined Publication No. 2000-164472 and Japanese Patent Unexamined Publication No. 2003-338432).